Both なくす (nakusu) and 失う (うしなう, ushinau) mean “to lose,” but they refer to very different kinds of loss. Choosing the wrong one will sound unnatural, so understanding the distinction is essential for natural Japanese.
| なくす (nakusu) | 失う (ushinau) | |
|---|---|---|
| Core meaning | To lose (a physical object) | To lose (something important, abstract, or irreplaceable) |
| Objects | Everyday items: keys, wallet, phone | Life, job, trust, opportunity, a person |
| Feeling | Neutral — careless or accidental misplacing | Weighty — serious, often painful loss |
| Register | Casual to standard | Standard to literary |
なくす — Losing a Physical Object
なくす is used for everyday misplacing or losing physical items. It is often accidental and not particularly serious in tone.
- 鍵をなくした。— I lost my key.
- また財布をなくした！— I lost my wallet again!
- スマホをなくしたかもしれない。— I might have lost my smartphone.
- パスポートをなくさないように注意して。— Be careful not to lose your passport.
Key: if it’s a concrete, physical object you can misplace or drop — use なくす.
失う — Losing Something Important or Irreplaceable
失う is used for serious, significant loss. It carries emotional weight and is appropriate when something valuable, abstract, or irreplaceable is lost.
- 信頼を失った。— I lost (someone’s) trust.
- 彼は仕事を失った。— He lost his job.
- 戦争で多くの命が失われた。— Many lives were lost in the war.
- 記憶を失う。— To lose one’s memory.
- チャンスを失った。— I lost the opportunity.
Key: if the loss is serious, painful, or abstract — use 失う.
The Gray Area: Can You Use Either?
Some objects can appear with both verbs, but the nuance shifts:
| Sentence | Kanji | Nuance |
|---|---|---|
| お金をなくした。 | なくす | I misplaced / accidentally lost some money. |
| 財産を失った。 | 失う | I lost my fortune (serious financial loss). |
| 携帯をなくした。 | なくす | I lost my phone (careless/accidental). |
| 大切なものを失った。 | 失う | I lost something dear to me (deep emotional loss). |
Is it a small, everyday physical object?
YES → なくす (lost my keys, wallet, etc.)
Is it something important, abstract, or serious?
YES → 失う (lost trust, job, life, memory)Natural Conversations
どうしたの？困った顔してるけど。— What’s wrong? You look worried.
定期券をなくしたかも。どこにあるか全然わからない。— I might have lost my commuter pass. I have no idea where it is.
あの有名な選手、引退したんだって。— I heard that famous athlete retired.
ほんとに？チームはすごく大事な存在を失ったね。— Really? The team has lost such an important presence.
Common Mistakes
Mistake: Using 失う for misplacing everyday objects.
❌ 鍵を失った。(sounds dramatic, like you’ll never see them again)
✅ 鍵をなくした。(natural — I can’t find my keys)
Mistake: Using なくす for serious, abstract loss.
❌ 信頼をなくした。(it actually does work colloquially!)
✅ 信頼を失った。(more natural and appropriate)
Note: 信頼をなくす is actually used informally — native speakers do say it. But 失う is more standard and appropriate for serious contexts.
Quick Quiz
Choose なくす or 失う:
1. 彼女はがんで視力を___してしまった。(She lost her eyesight due to cancer.)
2. 傘を___ちゃった。また新しいの買わないと。(I lost my umbrella again. Have to buy a new one.)
Answers: 1. 失う (失ってしまった) 2. なくす (なくしちゃった)
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